Explanations of chest pain in patients with chest pain, despite angiographically normal coronary arteries include abnormal coronary flow reserve and esophageal motility disorders. To ascertain the frequency of cardiac versus esophageal functional abnormalities in such patients, 50 patients with chest pain despite normal epicardial coronary arteries underwent measurement of coronary resistance during pacing at a heart rate of 150, heart rate of 150 after ergonovine, 0.5-0.3 mg intravenously and after dipyridamole 0.5-0.75 mg/kg intravenously. Those patients who had dynamic limitation in flow reserve to ergonovine and limited flow reserve after dipyridamole had a higher prevalence of esophageal motility disorders than those patients who had no vasoconstrictor response to ergonovine and had a normal flow reserve after dipyridamole. The high prevalence of abnormal esophageal motility in patients with dynamic limitation in coronary flow reserve suggests that this syndrome may be part of a generalized abnormality of smooth muscle reactivity.